Bluetooth Suab & Kev Ua Teeb Meem Digital: Arduino Framework: 10 Cov Kauj Ruam

2024 Tus sau: John Day | [email protected]. Kawg hloov kho: 2024-01-30 09:25

Ntsiab lus

Thaum kuv xav txog Bluetooth Kuv xav txog nkauj tab sis tu siab ntau microcontrollers tsis tuaj yeem ua suab paj nruag ntawm Bluetooth. Raspberry Pi tuaj yeem tab sis yog lub khoos phis tawj. Kuv xav txhim kho Arduino raws lub hauv paus rau microcontrollers los ua suab ntawm Bluetooth. Txhawm rau ua kom nruj kuv cov microcontroller cov leeg Kuv yuav ntxiv lub sijhawm tiag Digital Signal Processing (DSP) rau lub suab (lim siab dhau, lim qis thiab lim ntau yam sib zog). Txog cov txiv ntoo nyob saum, kuv yuav ntxiv lub vev xaib uas tuaj yeem siv los teeb tsa DSP wirelessly. Cov vis dis aus kos qhia qhov pib ntawm Bluetooth suab hauv kev nqis tes ua. Nws kuj tseem qhia kuv siv lub vev xaib los ua qee qhov kev ntsuas siab dhau, lim qis thiab lim ntau yam sib txawv. Thawj qhov siv Dynamic range compression lub hom phiaj ua rau muaj kev cuam tshuam raws li qhov piv txwv ntawm kev xaiv tsis zoo. Qhov piv txwv thib ob tshem tawm qhov kev cuam tshuam no.

Txog qhov haujlwm no, ESP32 yog lub microcontroller xaiv. Nws raug nqi tsawg dua £ 10 thiab tau ntim nrog ADCs, DACs, Wifi, Bluetooth Tsawg Zog, Bluetooth Classic thiab 240MHz dual-core processor. Onboard DAC tuaj yeem siv tshuab ua suab tab sis nws yuav tsis suab zoo. Hloov chaw, Kuv yuav siv Adafruit I2S lub tso suab tso suab los tsim cov kab tawm. Lub teeb liab no tuaj yeem xa mus rau ib qho system HiFi kom txuas ntxiv lub suab wireless rau koj qhov system HiFi uas twb muaj lawm.

Khoom siv

Vam tias, cov neeg tsim khoom feem ntau yuav muaj lub rooj ua mov ci, tus dhia, cov hlua USB, cov khoom siv hluav taws xob siv hluav taws xob thiab yuav tsuas yog siv £ 15 ntawm ESP32 thiab lub tso suab tso suab. Yog tias tsis yog, txhua ntu uas xav tau yog cov npe hauv qab no.

• Ib qho ESP32 - sim ntawm ESP32 -PICO -KIT thiab TinyPico - £ 9.50/ £ 24
• Adafruit I2S Stereo Decoder - £ 5.51
• Breadboard - £ 3- £ 5 txhua
• Jumper xov hlau - £ 3
• Wired headphones/Hi -Fi system - £££
• Push Headers lossis Soldering Iron - £ 2.10 / £ 30
• Micro USB cable - £ 2.10/ £ 3
• 3.5mm rau RCA txuas/ 3.5mm jack rau jack (lossis xijpeem koj tus neeg hais lus xav tau) - £ 2.40/ £ 1.50
• USB fais fab mov - £ 5

Kauj Ruam 1: Kev tsim kho - Breadboard

Yog tias koj yuav ESP32-PICO-KIT koj yuav tsis tas yuav siv cov koob li nws tau los ua ntej Cias muab nws tso rau ntawm daim ntawv qhia zaub mov.

Kauj Ruam 2: Kev Tsim Kho - Push Headers/soldering

Yog tias koj muaj cov hlau txuas, muab cov laug txuas rau lub tso suab tso suab raws li cov lus qhia ntawm Adafruit lub vev xaib. Thaum lub sijhawm sau ntawv kuv cov hlau txuas tau ua haujlwm uas raug kaw. Kuv tsis xav them nyiaj rau cov hlau txuas ib ntus yog li kuv txiav qee lub taub hau thawb los ntawm pimoroni. Kuv txiav lawv kom lawv yuav haum rau lub tso suab tso suab. Qhov no tsis yog qhov kev daws teeb meem zoo tshaj plaws (thiab tsis yog li cas lub taub hau tau npaj yuav siv) tab sis nws yog qhov kev xaiv pheej yig tshaj rau cov hlau txuas. Hloov lub taub hau txiav rau ntawm lub khob cij. Koj yuav tsum tsuas yog xav tau 1 kab ntawm 6 tus pin rau tus lej txiav txim. Koj tuaj yeem ntxiv lwm rau rau lwm sab rau kev ruaj ntseg tab sis qhov no tsis tsim nyog rau cov txheej txheem no. Cov pins los ntsaws lub taub hau rau hauv yog vin, 3vo, gnd, wsel, din thiab bclk.

Kauj Ruam 3: Kev Tsim Kho - Hlau Cov Pins Fais Fab

Muab lub tso suab tso suab tso rau ntawm lub thawb taub hau (vin, 3vo, gnd, wsel, din thiab bclk pins) thiab khov kho lawv ua ke. Ib zaug ntxiv, qhov no yuav tsum tau ua nrog cov hlau txuas tab sis kuv yuav tsum tau tsim kho. Koj yuav pom tias txhua cov xov hlau hauv cov lus qhia no yog xiav. Tias yog vim kuv tsis muaj ib lub xov hlau jumper yog li kuv txiav 1 xaim ntev mus ua tej daim me me. Tsis tas li, kuv yog cov neeg dig muag thiab tsis tshua mob siab rau xim hlau. Lub hwj chim pins tau txuas nrog hauv qab no:

3v3 (ESP32) -> rau vin ntawm lub tso suab tso suab

gnd (ESP32) -> rau gnd ntawm lub tso suab tso suab

Kauj Ruam 4: Kev Tsim Kho - I2S Txuas

Txhawm rau xa lub suab Bluetooth los ntawm ESP32 mus rau lub tso suab tso suab peb yuav siv txoj hauv kev ntawm kev sib txuas lus digital hu ua I2S. Lub tso suab tso suab yuav siv lub cim digital no thiab tig nws mus rau hauv lub teeb liab sib piv uas tuaj yeem txuas rau ntawm tus hais lus lossis HiFi. I2S tsuas yog xav tau 3 xov hlau thiab yog qhov ncaj ncees ncaj ncees kom nkag siab. Lub moos me ntsis (bclk) kab hloov siab thiab qis kom qhia tau tias me ntsis kis tshiab. Cov ntaub ntawv-tawm kab (dout) tig siab lossis qis los qhia seb qhov me ntsis muaj nqis ntawm 0 lossis 1 thiab lo lus xaiv kab (wsel) tig siab lossis qis los qhia seb sab laug lossis sab xis yog kis tau. Tsis yog txhua lub microcontroller txhawb I2S tab sis ESP32 muaj 2 kab I2S. Qhov no ua rau nws xaiv qhov pom tseeb rau txoj haujlwm no.

Kev thaiv kab mob yog raws li hauv qab no:

27 (ESP32) -> wsel (Lub tso suab tso suab)

25 (ESP32) -> din (Lub tso suab tso suab)

26 (ESP32) -> bclk (Lub tso suab tso suab)

Kauj Ruam 5: Txhim Kho BtAudio Library

Yog tias koj tsis tau muaj lawv teeb tsa nruab Arduino IDE thiab Arduino core rau ESP32. Thaum koj tau teeb tsa lawv mus ntsib kuv nplooj Github thiab rub tawm lub chaw cia khoom. Tsis pub dhau Arduino IDE nyob rau hauv Sketch >> suav nrog Tsev qiv ntawv >> xaiv "Ntxiv. ZIP tsev qiv ntawv". Tom qab ntawd xaiv cov ntawv rub tawm zip. Qhov no yuav tsum ntxiv kuv lub tsev qiv ntawv btAudio rau koj lub tsev qiv ntawv Arduino. Txhawm rau siv lub tsev qiv ntawv koj yuav tsum suav nrog lub taub hau cuam tshuam hauv Arduino kos duab. Koj yuav pom qhov no hauv cov kauj ruam tom ntej.

Kauj Ruam 6: Siv BtAudio Library

Thaum teeb tsa, txuas koj ESP32 rau koj lub khoos phis tawj ntawm micro USB thiab tom qab ntawd txuas koj lub tso suab tso suab rau koj tus hais lus nrog koj lub xov tooj 3.5mm. Ua ntej koj xa cov duab kos koj yuav xav hloov qee yam hauv Arduino tus khoos phis tawj. Tom qab koj tau xaiv koj pawg thawj coj koj yuav tsum tau hloov kho cov phiaj xwm muab faib raws li Cov Cuab Yeej >> Partition Scheme thiab xaiv ib qho "Tsis muaj OTA (APP loj)" lossis "Tsawg kawg SPIFFS (Loj APPS nrog OTA)". Qhov no yog qhov tsim nyog vim txoj haujlwm no siv ob qho WiFi thiab Bluetooth uas yog ob qho tib si nco lub tsev qiv ntawv hnyav. Thaum koj ua tiav qhov no upload cov duab kos hauv qab no mus rau ESP32.

#suav nrog

// Teeb lub npe ntawm lub cuab yeej audio btAudio audio = btAudio ("ESP_Speaker"); teeb tsa tsis muaj dab tsi () {// ntws cov ntaub ntawv audio rau ESP32 audio.begin (); // tso cov ntaub ntawv tau txais mus rau I2S DAC int bck = 26; int ws = 27; int dout = 25; audio. I2S (bck, dout, ws); } void voj () {}

Cov duab kos tuaj yeem muab faib ua 3 theem:

1. Tsim lub ntiaj teb btAudio cov khoom uas teev "Bluetooth lub npe" ntawm koj ESP32
2. Kho ESP32 kom tau txais lub suab nrog btAudio:: pib txheej txheem
3. Teeb I2S tus pin nrog btAudio:: I2S txoj kev.

Nov yog nws ntawm software sab! Tam sim no txhua yam koj yuav tsum ua yog pib Bluetooth txuas rau koj ESP32. Tsuas yog luam theej duab rau cov cuab yeej tshiab ntawm koj lub xov tooj/laptop/MP3 player thiab "ESP_Speaker" yuav tshwm sim. Thaum koj zoo siab tias txhua yam ua haujlwm (ntaus nkauj) koj tuaj yeem txuas ESP32 ntawm koj lub computer. Fais nws nrog USB fais fab mov thiab nws yuav nco qab tus lej kawg uas koj tau tshaj tawm rau nws. Txoj kev no, koj tuaj yeem tso koj li ESP32 zais tom qab koj li HiFi system ib txhis.

Kauj Ruam 7: DSP - Lim

Txuas tus Neeg Tau Txais Nrog Kev Ua Teeb Meem Digital

Yog tias koj ua raws txhua kauj ruam (thiab kuv tsis tau tso dab tsi tawm) tam sim no koj muaj lub Bluetooth ua haujlwm tau zoo rau koj li kab ke HiFi. Thaum qhov no txias nws tsis tshua thawb lub microcontroller rau nws qhov txwv. ESP32 muaj ob lub cores ua haujlwm ntawm 240MHz. Qhov ntawd txhais tau tias txoj haujlwm no nyob deb tshaj li tus txais. Nws muaj lub peev xwm los ua tus txais Bluetooth nrog Digital Signal Processor (DSP). DSPs qhov tseem ceeb ua cov lej ua haujlwm ntawm lub teeb liab hauv lub sijhawm tiag. Ib txoj haujlwm muaj txiaj ntsig hu ua Digital Filtering. Cov txheej txheem no ua rau cov zaus qis dua hauv cov cim hauv qab no lossis siab dua qee qhov kev txiav tawm, nyob ntawm seb koj puas siv lub siab-dhau lossis lim qis.

Cov lim dej siab dhau

High-Pass lim dej ua rau cov zaus qis dua hauv qab cov qhab. Kuv tau tsim lub tsev qiv ntawv lim rau Arduino systems raws li cov cai los ntawm earlevel.com. Qhov sib txawv tseem ceeb yog tias kuv tau hloov cov qauv hauv chav kawm los tso cai rau kev tsim cov lim dej ntau dua kom yooj yim dua. Kev txiav txim siab lim lim txwv ntau zaus dhau ntawm koj qhov kev txiav tawm zoo dua tab sis lawv xav tau ntau dua kev suav. Txawm li cas los xij, nrog kev siv tam sim no, koj tseem tuaj yeem siv qhov kev txiav txim thib 6 rau lub suab tiag-lub sijhawm!

Cov duab kos yog tib yam li ib qho pom nyob hauv cov kauj ruam dhau los tshwj tsis yog tias peb tau hloov lub voj loj. Txhawm rau pab lim dej peb siv btAudio:: createFilter txoj kev. Txoj kev no lees txais 3 qhov kev sib cav. Thawj yog tus naj npawb ntawm lim cascades. Tus naj npawb ntawm lim cascades yog ib nrab qhov kev txiav txim ntawm lub lim. Txog rau qhov kev txiav txim thib 6, thawj qhov kev sib cav yuav tsum yog 3. Rau qhov kev txiav txim zaum thib 8, nws yuav yog 4. Qhov kev sib cav zaum thib ob yog qhov kev txiav tawm. Kuv tau teeb tsa qhov no rau 1000Hz kom muaj txiaj ntsig zoo rau cov ntaub ntawv. Thaum kawg, peb hais qhia yam hom filer nrog qhov kev sib cav zaum thib peb. Qhov no yuav tsum yog txoj kev hla dhau rau qhov lim siab hla thiab hla hla rau qhov lim qis. Tsab ntawv hauv qab no hloov qhov txiav tawm ntawm qhov zaus ntawm 1000Hz thiab 2Hz. Koj yuav tsum hnov qhov ua tau zoo ntawm cov ntaub ntawv.

#suav nrog

btAudio suab = btAudio ("ESP_Speaker"); teeb tsa tsis muaj dabtsis () {audio.begin (); sib = 26; int ws = 27; int dout = 25; audio. I2S (bck, dout, ws); } void loop () {ncua (5000); audio.createFilter (3, 1000, highpass); ncua (5000); audio.createFilter (3, 2, highpass); }

Cov lim dej tsawg

Cov lim dej tsawg dhau ua qhov sib txawv ntawm cov lim siab dhau thiab tshem tawm cov zaus ntau dua ib qho zaus. Lawv tuaj yeem ua tiav hauv tib txoj kev raws li cov lim lim siab tshwj tsis yog tias lawv xav tau hloov qhov kev sib cav zaum thib peb mus rau qis. Rau cov duab hauv qab no kuv hloov qhov kev txiav qis qis ntawm 2000Hz thiab 20000Hz. Vam tias, koj yuav hnov qhov txawv. Nws yuav tsum tau suab muffled heev thaum lub lim qis dhau ntawm 2000Hz.

#suav nrog

btAudio suab = btAudio ("ESP_Speaker"); teeb tsa tsis muaj dabtsis () {audio.begin (); sib = 26; int ws = 27; int dout = 25; audio. I2S (bck, dout, ws); } void loop () {ncua (5000); audio.createFilter (3, 2000, lowpass); ncua (5000); audio.createFilter (3, 20000, lowpass); }

Kauj Ruam 8: DSP - Kev Sib Txawv Ntau Yam

Keeb kwm yav dhau

Dynamic range compression yog txheej txheem txheej txheem uas sim ua kom nrov nrov ntawm lub suab. Nws ua rau lub suab nrov nrov, uas nce siab dua ib qho chaw pib, mus rau qib uas nyob ntsiag to thiab tom qab ntawd, xaiv tau ua ob qho tib si. Qhov tshwm sim yog qhov ntau dua txawm tias mloog. Qhov no tuaj yeem pab tau tiag tiag thaum kuv tab tom saib yeeb yam nrog suab paj nruag yav dhau los thiab suab nrov heev. Hauv qhov no, tsuas yog nce ntim tsis pab li qhov no tsuas yog ua kom nrov tom qab suab paj nruag. Nrog rau qhov sib txawv ntawm qhov sib zog, Kuv tuaj yeem txo cov suab paj nruag tom qab nrov mus rau qib ntawm lub suab thiab hnov txhua yam kom raug dua.

Txoj Cai

Dynamic range compression tsis yog koom nrog txo qis lossis ua kom pom lub teeb liab. Nws yog qhov ntse dua qhov ntawd. Yog tias koj txo lub suab ntsiag to lub suab yuav raug txo kom zoo li lub suab nrov. Ib txoj hauv kev ib puag ncig qhov no yog kom pib lub teeb liab tab sis qhov no ua rau muaj qhov txawv txav loj. Kev sib zog ua kom muaj zog cuam tshuam nrog kev sib koom ua ke ntawm qhov pib qhov muag thiab lim kom txo qis qhov cuam tshuam ib qho yuav tau txais yog tias koj yuav pib/kaw lub teeb liab. Qhov tshwm sim yog lub teeb liab uas lub suab nrov tau "clipped" yam tsis muaj qhov cuam tshuam thiab cov neeg nyob ntsiag to tau tso tseg raws li lawv nyob. Cov cai hauv qab no hloov pauv ntawm peb qib sib txawv.

1. Compression nrog distortion
2. Compression tsis muaj distortion
3. Tsis muaj Compression

#suav nrog

btAudio suab = btAudio ("ESP_Speaker"); teeb tsa tsis muaj dabtsis () {audio.begin (); sib = 26; int ws = 27; int dout = 25; audio. I2S (bck, dout, ws); } void loop () {ncua (5000); audio.compress (30, 0.0001, 0.0001, 10, 10, 0); ncua (5000); audio.compress (30, 0.0001, 0.1, 10, 10, 0); ncua (5000); audio.decompress (); }

Dynamic range compression yog qhov nyuaj thiab btAudio:: compression txoj kev muaj ntau yam tsis. Kuv yuav sim thiab piav qhia lawv (raws li) ntawm no:

1. Threshold - Qib uas lub suab tau txo qis (ntsuas hauv decibels)
2. Lub sijhawm tawm tsam - Lub sijhawm nws yuav siv rau lub tshuab cua kom pib ua haujlwm thaum lub sijhawm pib tau dhau mus
3. Lub sijhawm tso tawm - Lub sijhawm nws siv rau lub tshuab cua kom tsis ua haujlwm.
4. Txo Cov Piv Txwv - qhov cuam tshuam uas lub suab raug kaw.
5. Lub hauv caug Dav - Qhov dav (hauv decibels) nyob ib ncig ntawm qhov pib uas lub tshuab cua ua haujlwm ib nrab (ntau lub suab zoo dua).
6. Qhov nce (decibels) ntxiv rau lub teeb liab tom qab nrawm (nce/txo ntim)

Qhov hnov tsis zoo hauv thawj qhov kev siv ntawm kev sib zog yog vim tias qhov pib qis heev thiab ob lub sijhawm tawm tsam thiab lub sijhawm tso tawm yog luv heev ua rau muaj kev coj tus cwj pwm nyuaj. Qhov no tau daws meej meej hauv rooj plaub thib ob los ntawm kev nce lub sijhawm tso tawm. Qhov no tseem ceeb ua rau lub tshuab ua kom ua haujlwm du dua. Ntawm no, kuv tsuas yog qhia pom qhov hloov pauv 1 qhov ntsuas tuaj yeem ua rau muaj txiaj ntsig zoo ntawm lub suab. Tam sim no nws yog koj tig los sim nrog cov ntsuas sib txawv.

Kev Siv (kev ua lej ua lej - xaiv tau)

Kuv pom tias ua tsis tiav siv Dynamic range compression los ua qhov nyuaj. Lub algorithm xav kom hloov pauv 16-ntsis rau decibels thiab tom qab ntawd hloov nws rov qab mus rau 16-ntsis integer thaum koj tau ua tiav lub teeb liab. Kuv pom tias ib kab ntawm cov cai tau siv 10 microseconds los ua cov ntaub ntawv tso suab. Raws li lub suab tso suab piv txwv ntawm 44.1 KHz tawm tsuas yog 11.3 microseconds rau DSP qhov no tsis tuaj yeem lees paub qeeb …. Kuv tau txuas daim ntawv pdf nrog txhua qhov lej rau qhov txaus siab tiag. Nws nyuaj, koj tau ceeb toom!

Kauj Ruam 9: Wifi Interface

Tam sim no koj muaj tus neeg txais Bluetooth muaj peev xwm ua haujlwm DSP lub sijhawm tiag tiag. Tu siab, yog tias koj xav hloov ib qho ntawm DSP qhov ntsuas koj yuav xav tau kev sib txuas los ntawm koj li HiFi, xa daim duab tshiab thiab tom qab ntawd rov txuas dua. Qhov no yog clunky. Txhawm rau kho qhov no kuv tsim lub vev xaib uas koj tuaj yeem siv los kho txhua DSP qhov tsis tau rov txuas rau koj lub khoos phis tawj. Daim duab kos los siv lub vev xaib xaib yog hauv qab no.

#suav nrog

#suav nrog btAudio suab = btAudio ("ESP_Speaker"); webDSP lub vev xaib; teeb tsa tsis muaj dab tsi () {Serial.begin (115200); audio.begin (); sib = 26; int ws = 27; int dout = 25; audio. I2S (bck, dout, ws); // hloov nrog koj li WiFi ID thiab tus lej cim siv tus lej char* ssid = "SSID"; const char* password = "PASSWORD"; web.begin (ssid, password, & suab); } tsis muaj dab tsi voj () {web._server.handleClient (); }

Txoj cai muab tus IP chaw nyob rau koj ESP32 uas koj tuaj yeem siv nkag mus rau lub vev xaib. Thawj zaug koj siv cov cai no koj yuav tsum muaj nws txuas rau koj lub khoos phis tawj. Txoj hauv kev ntawd koj tuaj yeem pom tus IP chaw nyob uas tau muab rau koj ESP32 ntawm koj tus lej saib. Yog tias koj xav nkag mus rau lub vev xaib no yooj yim nkag mus rau tus IP chaw no rau hauv txhua lub web browser (kuaj ntawm chrome).

Txog tam sim no peb yuav tsum paub txog txoj hauv kev qhib lub Bluetooth thiab I2S. Qhov sib txawv tseem ceeb yog kev siv cov khoom webDSP. Qhov khoom siv no siv koj li SSID Wifi thiab tus lej cim raws li kev sib cav nrog rau tus taw qhia rau btAudio yam khoom. Hauv lub voj tseem ceeb, peb txuas ntxiv tau txais cov khoom webDSP los mloog cov ntaub ntawv nkag los ntawm lub vev xaib thiab tom qab ntawd hloov kho DSP tsis. Raws li qhov kev kaw, nws yuav tsum tau sau tseg tias ob qho tib si Bluetooth thiab Wifi siv tib lub xov tooj cua ntawm ESP32. Qhov no txhais tau tias koj yuav tsum tau tos txog 10 vib nas this los ntawm thaum koj nkag mus tsis ntawm lub vev xaib mus txog thaum cov ntaub ntawv mus txog rau ESP32.

Kauj ruam 10: Cov phiaj xwm yav tom ntej

Vam tias, koj tau nyiam cov lus qhia no thiab tam sim no muaj Bluetooth Audio thiab DSP ntxiv rau koj li HiFi. Txawm li cas los xij, Kuv xav tias muaj ntau chav rau kev loj hlob hauv txoj haujlwm no thiab kuv tsuas yog xav taw qhia qee qhov lus qhia yav tom ntej uas kuv yuav coj mus.

• Pab kom Wifi streaming ntawm lub suab (rau lub suab zoo tshaj)
• Siv I2S lub microphone kom pab tau lub suab lus txib
• txhim kho WiFi tswj qhov sib npaug
• Ua kom nws zoo nkauj (breadboard tsis nrov nrov tsim cov khoom lag luam)

Thaum kuv tau txais ib puag ncig los ua raws cov tswv yim no kuv yuav ua kom muaj kev qhia ntau ntxiv. Los yog tej zaum lwm tus neeg yuav tau txais cov yam ntxwv no ua. Qhov ntawd yog kev xyiv fab ntawm kev ua txhua yam qhib qhov chaw!